Also, as Balfro mentioned, he and I both read through USM and took notes of the dates. We've compared notes, and I have the rough timeline compiled (I did the same thing for Ultimates, which I believe I posted in a thread at some point last year). I have since gone through X-Men and Fantastic Four with the same goal. After I read through all the minis, I should be able to painstakingly compile an as-accurate-as-possible timeline of the UU. So keep your eyes peeled over the next few months!
Now, as far as dates go, they're irrelevant. They happen "now." This year's "now" would be 2012 and the "now" from ten years ago would be 2002, but they're only about two to three years apart.